The everlasting Gobstoppers are a fictional and real life candy from the Wonka Candy Company. In the book and the films, the Everlasting Gobstopper jawbreaker (hence "gobstopper" which is gobble + stopper) that never gets smaller (hence "everlasting"). They are small, but very hard due to the longevity function. If one were to try chewing a Gobstopper, that someone would break all of their teeth out.